High Resolution 13C ad 31P NMR studies of E.coli, yeast and perfused mouse liver will be continued during the next year. In E. coli we are particularly interested in measureng the ATPase rate constants as a funcion of membrane energization by saturation transfer of the 31P resonances. The signal-to-noise improvement obtained by the 20 mm NMR tubes of E. coli will allow us to measure these rate constants even when they are slower than in fully energized cells. We also plan to continue our studies of the chemotactic response in E. coli. In yeast we will continue our investigations of the control of glycolysis concentrating on determining the metabolite control responsible for the Pasteur Effect. In perfused mouse liver and suspensions of rat hepatocytes we plan to continue our study of hormonal effect upon the gluconeogenic pathway. In particlar the differences already observed in pyruvate kinase activity between euthyroid and hyperthyroid cells will be investigated further. The effect of glucagon upon the gluconeogenic pathway will be studied in more detail in an attempt to obtain a simultaneous picture of its broad effects.